The abstract is your showcase. A good abstract provides visibility. This leads to citations, collaboration and impact
A bad abstract puts people off. Good research may go unread and unused.
Write the abstract last
Write concise versions of the background and aim/hypothesis. No more than one or two sentences.
Select key phrases from your methods section, but don't repeat the aim.
Select key phrases from the results and look for the concluding statement of paper.
Arrange words and phrases from steps 2-4 under appropriate headings.
Make sure the abstract does not contain new information, undefined abbreviations, unnecessary methods or reference citations
Remove unnecessary info and check flow of sentences
Check for consistency between abstract and paper ( by all authors)
Ask colleagues to read abstract - does it make sense? Could they understand your study? Does the writing flow? Are there typos?
Reread the journal instructions for abstracts to make sure it meets word count and style-format requirements. You don't want to waste time re-submitting for minor changes that careful preparation could have avoided.
adapted from Mary Nishikawa
'Tips for writing an effective, marketable abstract'
Video - How to write an Abstract: Some useful tips by Editage Insights
Preparing for Submission - International Committee of Medical Journal Editors Recommendations